Discovering the Laws of THermodynamics
“THE LAWS OF THERMODYNAMICS SMELL OF THEIR HUMAN ORIGINS” REFERS TO THE FACT THAT MOST OF THE LAWS OF THERMODYNAMICS WERE INSPIRED AT FIRST BY INDIVIDUALS INVESTIGATING NOT PHYSICS S OR HEAT ITSELF, BUT OTHER SUBJECTS OF HUMAN INTEREST, LIKE MEDICINE OR ENGINEERING. FOR EXAMPLE, THE MAN WHO FIRST PROPOSED THE FIRST LAW OF THERMODYNAMICS, ROBERT JULIUS MAYER, WAS A PHYSICIAN. HE WAS FIRST INVESTIGATING WHY VENOUS BLOOD WOULD REMAIN RED IN THE TROPICS. HE THEORIZED THAT SINCE THE TROPICS ARE HOTTER, THE BODY NEEDS LESS COMBUSTION TO FUEL ITSELF, SO LESS CARBON IS PRODUCED, ALLOWING FOR THE VENOUS BLOOD TO REMAIN RED. THIS LEADS MAYER TO REALIZE THAT THE BODY DOES NOT JUST PRODUCE HEAT, BUT ALSO PRODUCES MECHANICAL WORK, WHICH RESULTS IN FRICTION AND MORE HEAT. HE THEN REALIZED THAT THESE DIFFERENT TYPES OF ENERGY PRODUCED BY THE BODY ARE INTERCHANGEABLE. HE EXPANDED THIS IDEA FROM JUST THE BODY TO THE NATURAL WORLD IN GENERAL, CREATING THE FIRST LAW OF THERMODYNAMICS FROM OBSERVATIONS OF BLOOD.
THE SECOND LAW WAS A SIMILAR CASE. SADI CARNOT, A FRENCH MILITARY ENGINEER IN THE EARLY 19TH CENTURY, WAS AT FIRST INTERESTED IN HOW TO MAKE A MORE EFFICIENT STEAM ENGINE. WITH THE INCREASING IMPORTANCE OF THE STEAM ENGINE, ENGINEERS WERE SEEKING WAYS TO IMPROVE THE EFFICIENCY AND POWER OF THEIR ENGINES. WHILE MANY ENGINEERS IMPROVED THEIR ENGINES VIA TRIAL AND ERROR, CARNOT TOOK A MORE THEORETICAL APPROACH, FRAMING A GENERAL THEORY OF STEAM ENGINES. HE REALIZED THAT HEAT WAS A BYPRODUCT OF THE ENGINE, AND THAT HEAT WAS GOING TO BE LOST TO THE ENVIRONMENT, LEADING TO THE SECOND LAW OF THERMODYNAMICS: HEAT FLOWS OUTWARD. ALTHOUGH CARNOT DID IN FACT TAKES A GENERAL, THEORETICAL APPROACH TOWARDS HEAT, IT WAS LESS HIS INHERENT INTEREST IN HEAT, AND MORE ABOUT HIS INTEREST IN MAKING A MORE EFFICIENT AND POWERFUL ENGINE BY UNDERSTANDING THE CONCEPTS THAT UNDERLIE HOW HEAT POWERS THE ENGINE ITSELF.
THROUGHOUT THE BEGINNING OF THE INVESTIGATIONS INTO HEAT, MANY DISCOVERIES WERE MADE BY NOT SCIENTISTS DEVOTED TO THE STUDY AND RESEARCH OF PHYSICS AND HEAT, BUT OBSERVANT INDIVIDUALS WHO NOTED THAT HEAT FOLLOWED CERTAIN LAWS, WHICH INTERESTED THEM AND MADE THEM FURTHER INVESTIGATE HOW HEAT WAS GENERATED AND TRANSFERRED. WITH THIS INITIAL INTEREST STARTED, PEOPLE STARTED INVESTIGATING HEAT ITSELF AS A SUBJECT OF INTEREST, AND NOT AS SOME INCIDENTAL DISCOVERY.
THE SECOND LAW WAS A SIMILAR CASE. SADI CARNOT, A FRENCH MILITARY ENGINEER IN THE EARLY 19TH CENTURY, WAS AT FIRST INTERESTED IN HOW TO MAKE A MORE EFFICIENT STEAM ENGINE. WITH THE INCREASING IMPORTANCE OF THE STEAM ENGINE, ENGINEERS WERE SEEKING WAYS TO IMPROVE THE EFFICIENCY AND POWER OF THEIR ENGINES. WHILE MANY ENGINEERS IMPROVED THEIR ENGINES VIA TRIAL AND ERROR, CARNOT TOOK A MORE THEORETICAL APPROACH, FRAMING A GENERAL THEORY OF STEAM ENGINES. HE REALIZED THAT HEAT WAS A BYPRODUCT OF THE ENGINE, AND THAT HEAT WAS GOING TO BE LOST TO THE ENVIRONMENT, LEADING TO THE SECOND LAW OF THERMODYNAMICS: HEAT FLOWS OUTWARD. ALTHOUGH CARNOT DID IN FACT TAKES A GENERAL, THEORETICAL APPROACH TOWARDS HEAT, IT WAS LESS HIS INHERENT INTEREST IN HEAT, AND MORE ABOUT HIS INTEREST IN MAKING A MORE EFFICIENT AND POWERFUL ENGINE BY UNDERSTANDING THE CONCEPTS THAT UNDERLIE HOW HEAT POWERS THE ENGINE ITSELF.
THROUGHOUT THE BEGINNING OF THE INVESTIGATIONS INTO HEAT, MANY DISCOVERIES WERE MADE BY NOT SCIENTISTS DEVOTED TO THE STUDY AND RESEARCH OF PHYSICS AND HEAT, BUT OBSERVANT INDIVIDUALS WHO NOTED THAT HEAT FOLLOWED CERTAIN LAWS, WHICH INTERESTED THEM AND MADE THEM FURTHER INVESTIGATE HOW HEAT WAS GENERATED AND TRANSFERRED. WITH THIS INITIAL INTEREST STARTED, PEOPLE STARTED INVESTIGATING HEAT ITSELF AS A SUBJECT OF INTEREST, AND NOT AS SOME INCIDENTAL DISCOVERY.